CRC REEF RESEARCH CENTRE TECHNICAL REPORT No. 19

An Atlas Of Tropical Cyclones In The Great Barrier Reef Region, 1969-1997.

M.L. Puotinen, James Cook University
T.J. Done, Australian Institute of Marine Science
W.C. Skelly, James Cook University

EXECUTIVE SUMMARY

Cyclones are among the most important natural agents of disturbance on coral reefs in non-equatorial regions. The severity, extent and frequency of cyclonic damage on the Great Barrier reef is such that almost all reefs have been impacted by cyclones at least once in the last 20 years. Both direct effects such as cyclone generated waves, and indirect effects such as turbid, sediment laden river plumes can substantially alter the physical structure and community composition of reefs. These disturbances create a complex pattern of reef status within the GBR, with different reefs being at various stages of recovery from cyclonic damage. From a management viewpoint, it is important to understand not only the statistical probability of natural damage to reefs in different parts of the GBR, but also to be able to determine which reefs have experienced specific frequencies of cyclonic disturbances in the past, and how long it has been since the last disturbance. This atlas provides just this type of information, and a great deal more, through a comprehensive series of maps and tables. It will be of considerable use to managers wishing to determine the likely status of a particular reef and its vulnerability to further anthropogenic stress.

The production of this atlas came about as a result of a personal request during a CRC annual review of a project to develop detailed predictive models of cyclone damage. This responsiveness on the part of the researcher to the immediate needs of managers is an excellent example of the advantages of the close cooperative relationship which has developed between certain managers and researchers within the Cooperative Research Centre. As an interim product of this CRC project, this atlas will be frequently referred to, both by managers and, I suspect, many researchers.

Tropical cyclones generate high winds, large waves and often massive rainfall that can cause major damage to the coral reefs of the Great Barrier Reef Region (GBRR). Damage to reefs from several recent cyclones has been documented: Winifred (1986); Ivor (1990); Joy (1990); Sadie (1993); Celeste (1996); and Justin (1997). Observed cyclone damage ranged from minor breakage of fragile branching corals to major losses of coral coverage over entire reefs.

This atlas provides a first step towards understanding the risk of cyclone damage to coral reefs and other associated ecosystems of the GBRR by facilitating an examination of the history (climatology) of cyclones across the region over time.

Through an extensive set of maps and charts and relevant background information, this document provides: 1) a compilation of the paths and basic characteristics of tropical cyclones through the GBRR from 1969 to 1997 and 2) an exploration of the spatial and temporal patterns of cyclone activity across the region. As a reference document, this atlas can be used to address a wide range of questions such as:

• What is the history of cyclone activity near a particular location (a reef, a pontoon, an island resort, a port)?
• Was a cyclone nearby at a particular time (could a cyclone have contributed to an observed pattern of damage on a reef, a seagrass bed)?
• Which areas of the GBRR have had the most frequent or the most intense cyclones?

THIS PUBLICATION IS CITED AS:
Puotinen, M.L., Done, T.J., & Skelly, W.C. (1997)
An atlas of tropical cyclones in the Great Barrier Reef Region, 1969-1997.
Technical Report No. 19
Townsville; CRC Reef Research Centre Ltd, 201 pp.

ISBN 1 876054 51 4

A full copy of this report may be obtained from the author(s), and through the following libraries: